Language & WorldFact
The "first floor" is downstairs in New York and upstairs in London.
In Europe, most Commonwealth countries and much of Latin America the ground floor is 0 and the "first floor" is one flight up. In the USA, Canada, China, Japan, Russia and Norway, the "first floor" is the ground floor. The top level of a seven-storey building is therefore the "6th floor" in Britain and the "7th floor" in America.
Useful: For hotel or office addresses abroad, count the storeys instead of trusting the label.
Source: en.wikipedia.org